Carburetor for internal combustion engines



July 16, 1940. BECK CARBURETOR FOR INTERNAL COMBUSTION ENGINES FiledFeb. 16, 1937 4 5 2/ u u r 1 a... m Vi l /2 M JW w a 24 m. n F NUH b -ML Patented July 16, 1940 UNITED. STATES CARBURETOR FOR INTERNALCOMBUSTION ENGINES- Ludwig Beck, Berlin, Germany, assignor of one:

third to Ludwig Bertele, Berlin-Steglitz, Germany, and one-third toAlwin Dusterloh,

Sprockhovel, Germany Application February 16, 1937, Serial No. 126,039In Germany February 18, 1936 3 Claims.

This invention relates to an improved carburetor for internal combustionengines, especially for such internal combustion engines as are employedfor driving vehicles. This improved car- -,1 buretor is distinguished byits particularly low consumption of fuel without impairing in any waythe flexibility with which the speed of the motor or engine follows thechanges in the position of the throttle valve.

The invention is illustrated diagrammatically and by way of example inthe accompanying drawing, in which- Fig. 1 shows a longitudinal sectionthrough a simple carburetor constructed according to the invention;

Fig. 2 is a similar representation showing a modified constructionalform of the carburetor and drawn on an enlarged scale relative to Fig.1;

Fig. 3 is an exterior view of the members connecting the throttle valveand the air valve of the carburetor shown in Fig. 2; and

Fig. 4 is partly an exterior view of, and partly a section through, amore complete carburetor vcorresponding generally to the one shown inFig. 1.

Referring first to the diagrammatic representation in Fig. l, in thisfigure all parts which do not pertain to the invention have beenomitted, as

.the drawing is merely intended to disclose the fundamental principle ofthe invention. In this figure of the drawing, the numeral l denotes thecarburetor channel which is provided with the known constriction 2 intowhich extends the nozzle 3 which communicates with the'fioat carsing(not shown) by means of a passage 4. The

sectional area of the passage through which the nozzle is supplied withfuel is so small that the nozzle 3 receives only such an amount of fuelas suffices for the lower range of speed of the motor. There is,however, provided another nozzle 5, which extends as a separate memberinto the carburetor channel I and communicates with two passages 6 andl, of which 6 connects the nozzle 5 with the fuel supply passage 4,whereas I connects said nozzle with an aperture 8 opening to theatmosphere and which serves for the admission of air and lies above, andconsiderably remote from, the fuel-level a-'o.

The aperture 8 is so ground as to present a flat face and stands behindthe valve plate 9 which is secured to the shaft ll] of the throttlevalve ll. When this valve is open, the aperture 8 is fully uncovered,but when the throttle valve is being closed, it closes the aperture 8 toa corresponding extent, whereby also the air entering into this apertureis correspondingly throttled.

The invention makes use of the principle that a nozzle connected with afuel supply passage, as well as with an air-supply passage, sucks in anddelivers a mixture of these fluids, and thatthe contents of the fuel inthe mixture will be the larger, the more the entrance of air is impeded.According to the present invention, said principle is utilized in such amanner that the nozzle 5 supplies fuel only in the range of the higherspeeds, which in the case of vehicles, for instance, may be a speed offrom 40 to km. per hour. In the lower speed ranges, the motor receivesfuel through first mentioned nozzle 3 which is inserted into the suctionchannel as a separate member, the sectional area of which is so small(say about one-half of the sectional area of a normal carburetor nozzle)that it can supply the motor with fuel in a sufficient amount only up tothat range of speed in which the supplemental nozzle commences to becomeactive. One succeeds in this way (it being presupposed that the valveplate 9 is shaped suitable to the purpose intended) in adjusting thesupply of fuel from the carburetor to the motor in the higher range ofspeed (in which normal carburetors operate uneconomically) accurately tothe actual necessary consumption of fuel by the motor. It is, therefore,possible to attain in normal driving conditions savings of from 15% to25% in com-- parison to the usual carburetors without impalring in theleast the braking capacity and the acceleration capacity, in that thesecapacities depend chiefiy upon the design of the nozzle 3 which, in thelower range of speed or in the case of a sudden closure of thethrottling valve (brakingby compression), acts as a normal carburetornozzle, the action of which in this manner is not affected by thesupplemental nozzle 5 because this nozzle can supply fuel solely in thehigher ranges of speed. In the lower speed ranges the active vacuum atthe nozzle 5 is so slight that it is insufficient to suck the fuelupwards from the deeply located fuel level a--b to and into the chamberIt, by the intermediary of which the nozzle 5 and the passage 6communicate with one another. If the vacuum active'at the nozzle 5 isincreased by opening the throttle-valve H, the delivery of the fuel byand through said nozzle will be restricted because of the fact that airenters into the chamber I2 through the passagel, whereby the amount offuel sucked in is prop erly regulated.

In orderv to adjust the carburetor correctly, the

chamber I2 is equipped with an air bleed passage,

adapted to be closed by a threaded valve, the head l3 of which isconnected with a lever M by means of a clip l5. The free end of saidlever is connected with a wire cable (not shown) terminating at theinstrument panel of the car. The valve 13 can be closed by pulling atthe above-mentioned wire cable, whereby a temporary excess of fuel issupplied in case the driver should desire a rapid acceleration of hiscar. Readjustment for winter condition, driving uphill, and the like, iseffected by a corresponding readjustment of the lever clip 15 relativelyto the head of the valve [3.

The supplemental nozzle 5 need not be arranged ahead of the throttlingvalve Ii, but may be located behind it with respect to the direction offlow of the air. sucked into the carburetor channel. A modificationdesigned in this manner is shown in Fig. 2, in which if) denotes thecarburetor channel which is contracted at the two portions I! and I8, ofwhich one lies ahead of the throttling valve I9 and theother lies behindit. Two nozzles are provided, of

which one extends into one contracted portion I? of the carburetorpassage and the other extends into the other contracted portion I8thereof. The lower nozzle 23 is the one which lies ahead of the throttlevalve I 9 with respect to the direction of flow of the air sucked in.Said lower nozzle is similar in design to commercial carburetor nozzlesand consists of the tube 20 and the hood 2| which is screwed onto saidtube 20. The tubular, portions of these members 20 and 2| formtwoconcentric annular spaces, of which the outer one communicates withthe passage 22 through which air is supplied into said outer space. Thesectional area of the nozzle 7 formed by the said members 20 and 2! isso reto run in the lower speed range, and is the only at the nozzle 24in Fig. 2).

stricted that the amount of fuel which can pass through it is onlysufficient to enable the motor feature by which the nozzle 23 isdistinguished from the commercial constructional forms.

Into the other contracted portion of the carburetor passage l6 extendsthe nozzle 24, which communicates with two passages, of which thepassage 25 extends downwardly to below the fuel level a-b and is at itslower end connected with the fuel supply passage 26. The other upperpassage 21 leads to a threaded valve 28 and to an aperture 29which,co-acts with a valve plate 30 that is rotatable on a pivot 3| andis connected with the shaft of the throttle valve H by means of a link33 and an arm 34. These members (30, 33, 34) are particularly well shownin Fig. 3, from which it appears that the valve plate 30 is wedge-shapedand is provided with an oblong tapered slot 36, by which the opening 29is gradually closed as the throttle valve is opened.

The valve plate 30 acts, therefore, reversely to the valve plate 9 ofFig. 1. This is necessary because, when the throttle valve is closed,the vacuum present ahead of the same (that is to say, at the nozzle SinFig. 1) is reduced; but is increased behind the throttle valve (that isto say, When the throttle valve is closed, the highest vacuum becomeseffective at the nozzle 24 and, therefore, enough air must enter throughthe passage 21 so that no fuel is sucked in.

The same is true of the lower speed range of the engine (slightly openedthrottle valve). For this reason the sides of the slot 36 extend atfirst parallel to one another so that the valve plate 30 leaves theaperture 29 open for an angle of turning of about 20% of full throttleopening. Only when the throttle valve has been further opened, the valveplate 30 commences to cover the slot 36 gradually more and more, wherebya correctly regulated determination of the amount of fuel sucked inthrough the nozzle 24 is rendered possible. .In the low speed range, themotor is supplied with fuel exclusively by means of the nozzle 20-23.

Fig. 4 shows a thoroughly perfected carburetor of a type, the principleof which has been disclosed in Fig. l, the device being seen in thedirection indicated by the arrow P in Fig. l. The float receptacle 3],which is designed as usual, communicates with the nozzle 38, which isconstructed in about the same manner as the nozzle Elle-23 of Fig. 2,the connection being established by the passage 39 which supplies fuelalso to the supplemental nozzle 40. The nozzles 38 and 40 extend intothe carburetor channel All which tapers from one end to the other andboth nozzles are located ahead of the throttle valve 42. Thenozzle 40communicates also with the air passage 43 which has a branch 44, at theouter end of which is arranged the valve plate 45 which is firmlyattached to the shaft 46 of the throttle valve. The more the throttlevalve is opened, the more the branch M will be opened by the slide 45.The upper end of the air passage 43 is likewise closed by a valve plate41, which is designed similar to the slide 30 (Fig. 3) and serves forregulating the carburetor to the proper operative condition. .The valveplate 41 is rigidly connected with an arm 48 having at its free end aneye 49 for connection with a wire cable, the other end of which leads tothe instrument panel of the car, whereby it is rendered possible toclose the passage 43 partially or completely, in order to producetemporarily an increased acceleration of the motor.

The carburetors described on the preceding pages can be equipped, ofcourse, with the usual accessories as, for instance, an auxiliarycarburetor. The carburetor shown in Fig. 4 has the adjusting screw 50 tobe used for adjusting the idling mixture when the motor is runningwithout load.

I claim:

1. Ina carburetor, a casing including a mixing chamber, a throttle valvein said chamber, normal speed and high speed fuel nozzles projectinginto said chamber, means for supplying fuel at a predetermined level tosaid nozzles including a passageway leading to said high speed nozzle, avalve for admitting air to said passageway above the level of fueltherein, said valve being closed at normal speed, a second valve foradmitting air to said passageway above the level of fuel therein, meansfor adjusting said second valve so that the amount of airadmittedthereby is sufficient to prevent fuel from being supplied tosaid high speed nozzle at normal speed, and means interconnecting thefirst said air admitting valve and said throttle valve whereby the firstsaid air admitting valve is opened only after said throttle valve hasbeen opened a predetermined extent and progressively further opened asthe throttle approaches wide open position.

2. In a carburetor, a casing including a mixing chamber, a main fuelnozzle projecting into said chamber, a throttle valve, a high speed fuelI nozzle projecting into said chamber, means for supplying fuel to saidnozzles, air venting means for controlling the supply of fuel. throughsaid high speed nozzle rendering the same inoperative to deliver fuel tothe mixing chamber while idling and unresponsive to successively greaterthrottle openings until a predetermined throttle opening is reached, andadditional valve means for regulating a supply of air to said high speednozzle operated thereafter in accordance with the throttle opening toprogressively decrease the rate at which the delivery of fuel from saidhigh speed nozzle increases with increased throttle openings.

3. In a carburetor, a casing including amix ing chamber, a main fuelnozzle projecting into said chamber, a throttle valve, a high speed fuelnozzle projecting into said chamber, means for supplying fuel to saidnozzles, means including a manually adjustable air valve for controllingthe admission of air to said high speed nozzle and thereby the deliveryof fuel from said high speed nozzle so that at any throttle openingbetween the idling position and a predetermined partially open positionno fuel is delivered from said high speed nozzle, and means including asecond air valve mechanically coupled with the throttle valve andeffective after the said predetermined throttle opening is passed forprogressively admitting air to said high speed nozzle and therebydecreasing the efiect of successively greater throttle openings on thesup- LUDWIG BECK.

